The GE Silicone I Tub and Tile 100% silicone is a permanently waterproof caulk for use in kitchens and baths as well as in plumbing applications. GE Silicone I Tub & Tile provides mold resistant product protection and never cracks, shrinks breaks down or washes away. GE Silicone I Tub and Tile caulk is permanently waterproof and it will not shrink, crack, or crumble over time like acrylic. Silicone chemically cures while acrylic is water-based (it simply dries as water escapes). Some acrylics can shrink up to 25 percent, leaving gaps and cracks for water to seep through. Those leaks can lead to water damage and mold growth. 100% Silicone sealant is widely considered to be the best caulk for re-caulking and sealing around bathtubs, showers and faucets as well as other areas in your home that will be exposed to water.